origin: (1665) → late Greek narthēx = giant fennel [the columns]
noun (adjective: Nar·the·cal)
Architecture has many words to describe things we might simply call "rooms" or "walls", but this particular room is located inside of a Church -- an area less formally referred to as a vestibule (inside room) or portico (outside porch) -- separate from the main worshipping area; an enclosed passage.
The purpose of the narthex was to allow those not eligible for admittance into the general congregation to hear and partake in the service. - Wikipeadia
*Today's word brought to you by the fact that I recently chanced to work inside one...
and because as a member of this community, I certainly cannot resist a word so cool-sounding!
(which also sounds like the name of a heavy metal group. lol)